Myeloid tissue | definition of myeloid tissue by Medical dictionary Myeloid tissue | definition of myeloid tissue by Medical dictionary Related to myeloid tissue: lymphoid tissue , haematopoiesis tissue adipose tissue connective tissue made of fat cells in a meshwork of areolar tissue. areolar tissue connective tissue made up largely of interlacing fibers. bony tissue osseous tissue . brown adipose tissue (brown fat tissue) brown fat . bursa-equivalent tissue (bursal equivalent tissue) a hypothesized lymphoid tissue in nonavian vertebrates including human beings, equivalent to the bursa of Fabricius in birds: the site of B lymphocyte maturation. It now appears that B lymphocyte maturation occurs primarily in the bone marrow. cancellous tissue the spongy tissue of bone. cartilaginous tissue the substance of cartilage. chordal tissue the tissue of the notochord. chromaffin tissue a tissue composed largely of chromaffin cells, well supplied with nerves and vessels; it occurs in the adrenal medulla and also forms the paraganglia of the body.

cicatricial tissue the dense fibrous tissue forming a cicatrix , derived directly from granulation tissue ; called also scar tissue . connective tissue the tissue that binds together and is the support of the various structures of the body; see also connective tissue . elastic tissue connective tissue made up of yellow elastic fibers, frequently massed into sheets. endothelial tissue peculiar connective tissue lining serous and lymph spaces. epithelial tissue a general name for tissues not derived from the mesoderm. erectile tissue spongy tissue that expands and becomes hard when filled with blood. fatty tissue connective tissue made of fat cells in a meshwork of areolar tissue. fibrous tissue the common connective tissue of the body, composed of yellow or white parallel elastic and collagen fibers. gelatinous tissue mucous tissue . granulation tissue material formed in repair of wounds of soft tissue, consisting of connective tissue cells and ingrowing young vessels; it ultimately forms cicatrix. gut-associated lymphoid tissue (GALT) lymphoid tissue associated with the gut, including the tonsils, Peyer's patches, lamina propria of the gastrointestinal tract, and appendix. indifferent tissue undifferentiated embryonic tissue.

interstitial tissue connective tissue between the cellular elements of a structure. lymphadenoid tissue tissue resembling that of lymph nodes, spleen, bone marrow, tonsils, and lymph vessels. lymphoid tissue a latticework of reticular tissue whose interspaces contain lymphocytes . mesenchymal tissue embryonic connective tissue composed of stellate cells and a ground substance of coagulable fluid. mucous tissue a jellylike connective tissue, such as occurs in the umbilical cord. Called also gelatinous tissue . muscular tissue the substance of muscle. myeloid tissue red bone marrow . nerve tissue (nervous tissue) the specialized tissue forming the elements of the nervous system. osseous tissue the specialized tissue forming the bones. reticular tissue (reticulated tissue) connective tissue composed predominantly of reticulum cells and reticular fibers. sclerous t's the cartilaginous, fibrous, and osseous tissues. skeletal tissue the bony, ligamentous, fibrous, and cartilaginous tissue forming the skeleton and its attachments. splenic tissue red pulp . subcutaneous tissue the layer of loose connective tissue directly under the skin.

tissue typing identification of tissue types for purposes of predicting acceptance or rejection of grafts and transplants . The process and purposes of tissue typing are essentially the same as for blood typing. The major difference lies in the kinds of antigens being evaluated. The acceptance of allografts depends on the hla antigens (HLA); if the donor and recipient are not HLA identical, the allograft is rejected, sometimes within minutes. The HLA genes are located in the major histocompatibility complex , a region on the short arm of chromosome 6, and are involved in cell-cell interaction, immune response , organ transplantation, development of cancer, and susceptibility to disease. There are five genetic loci, designated HLA-A, HLA-B, HLA-C, HLA-D, and HLA-DR. At each locus, there can be any of several different alleles. Each person inherits one chromosome 6 from the mother and one from the father; that is, each parent transmits to the child one allele for each kind of antigen (A, B, C, D, and DR).

If the parents are different at both alleles of a locus, the statistical chance of one sibling being identical to another is one in four (25 per cent), the chance of being identical at one allele only (half-identical) is 50 per cent, and the chance of a total mismatch is 25 per cent. Techniques for Tissue Typing. Histocompatibility testing involves several basic methods of assay for HLA differences. The most widely used method uses the polymerase chain reaction to compare the DNA of the person, organ, or graft being tested with known pieces of the genes encoding MHC antigens. The variability of these regions of the genes determines the tissue type of the subject. Serologic methods are used to detect serologically defined antigens on the surfaces of cells. In general, HLA-A, -B, and -C determinants are primarily measured by serologic techniques. A second method, involving lymphocyte reactivity in a mixed lymphocyte culture, for determining HLA-D or lymphocyte-defined antigens, is now only rarely used. Essentially, the serologic method is performed by incubating target lymphocytes (isolated from fresh peripheral blood) with antisera that recognize all known HLA antigens.

The cells are spread in a tray with microscopic wells containing various kinds of antisera and are incubated for 30 minutes, followed by an additional 60-minute complement incubation. If the lymphocytes have on their surfaces antigens recognized by the antibodies in the antiserum, the lymphocytes are lysed. A dye is added to show changes in the permeability of the cell membrane and cellular death. The proportion of cells destroyed by lysis indicates the degree of histologic incompatibility. If, for example, the lymphocytes from a person being tested for HLA-A3 are destroyed in a well containing antisera for HLA-A3, the test is positive for this antigen group. white adipose tissue (yellow adipose tissue) the adipose tissue composing the bulk of the body fat. my·e·loid tis·sue bone marrow consisting of the developmental and adult stages of erythrocytes, granulocytes, and megakaryocytes in a stroma of reticular cells and fibers, with sinusoidal vascular channels.

my·e·loid tis·sue (mī'ĕ-loyd tish'ū) Bone marrow consisting of the developmental and adult stages of erythrocytes, granulocytes, and megakaryocytes in a stroma of reticular cells and fibers, with sinusoidal vascular channels. myeloid tissue the tissue producing blood cells in vertebrates, normally located in bone marrow. myeloid Myeloid tissue | Define Myeloid tissue at Dictionary.com myeloid tissue Expand myeloid tissue n. Bone marrow consisting of the developmental and adult stages of red blood cells, granulocytes, and megakaryocytes in a stroma of reticular cells and fibers, with sinusoidal vascular channels. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. What is acute myeloid leukemia? What is acute myeloid leukemia? What are the key statistics about acute myeloid leukemia? What is acute myeloid leukemia?

Cancer starts when cells in a part of the body begins to grow out of control and can spread to other areas of the body. There are many kinds of cancer. Cells in nearly any part of the body can become cancer. To learn more about how cancers start and spread, see What Is Cancer? Leukemias are cancers that start in cells that would normally develop into different types of blood cells. Here we will talk about acute myeloid leukemia (AML). Acute myeloid leukemia (AML) has many other names, including acute myelocytic leukemia, acute myelogenous leukemia, acute granulocytic leukemia, and acute non-lymphocytic leukemia. “Acute” means that this leukemia can progress quickly if not treated, and would probably be fatal in a few months. “Myeloid” refers to the type of cell this leukemia starts from. Most cases of AML develop from cells that would turn into white blood cells (other than lymphocytes), but some cases of AML develop in other types of blood-forming cells. The different types of AML are listed in “ How is acute myeloid leukemia classified?

” AML starts in the bone marrow (the soft inner part of certain bones, where new blood cells are made), but in most cases it quickly moves into the blood. It can sometimes spread to other parts of the body including the lymph nodes, liver, spleen, central nervous system (brain and spinal cord), and testicles. Other types of cancer can start in these organs and then spread to the bone marrow. But these cancers that start elsewhere and then spread to the bone marrow are not leukemias. Normal bone marrow, blood, and lymphoid tissue To understand the different types of leukemia, it helps to know about the blood and lymph systems. Bone marrow Bone marrow is the soft inner part of some bones such as the skull, shoulder blades, ribs, pelvic (hip) bones, and backbones. The bone marrow is made up of a small number of blood stem cells, more mature blood-forming cells, fat cells, and supporting tissues that help cells grow. Inside the bone marrow, blood stem cells develop into new blood cells. During this process, the cells become either lymphocytes (a kind of white blood cell) or other blood-forming cells, which are types of myeloid cells.

These other blood-forming cells can develop into red blood cells, white blood cells (other than lymphocytes), or platelets. Types of blood cells Red blood cells carry oxygen from the lungs to all other tissues in the body, and take carbon dioxide back to the lungs to be removed. Having too few red blood cells in the body (called anemia) can make you feel tired, weak, and short of breath because your body tissues are not getting enough oxygen. Platelets are actually cell fragments made by a type of bone marrow cell called the megakaryocyte. Platelets are important in stopping bleeding. They help plug up holes in blood vessels caused by cuts or bruises. Having too few platelets (called thrombocytopenia) may cause you to bleed or bruise easily. White blood cells help the body fight infections. Having too few white blood cells weakens your immune system and can make you more likely to get an infection. Types of white blood cells Lymphocytes are mature, infection-fighting cells that develop from lymphoblasts, a type of blood stem cell in the bone marrow. Lymphocytes are the main cells that make up lymphoid tissue, a major part of the immune system.

Lymphoid tissue is found in lymph nodes, the thymus (a small organ behind the breast bone), the spleen, the tonsils and adenoids, and is scattered throughout the digestive and respiratory systems and the bone marrow. There are 2 main types of lymphocytes: B lymphocytes (B cells) protect the body from invading germs by developing (maturing) into plasma cells, which make proteins called antibodies. The antibodies attach to the germs (bacteria, viruses, and fungi), which helps other types of white blood cells recognize and destroy them. T lymphocytes (T cells) can recognize cells infected by viruses and directly destroy these cells. They also help regulate the immune response. Granulocytes are mature, infection-fighting cells that develop from myeloblasts, a type of blood-forming cell in the bone marrow. Granulocytes have granules that show up as spots under the microscope. These granules contain enzymes and other substances that can destroy germs, such as bacteria. The 3 types of granulocytes – neutrophils, basophils, and eosinophils – are distinguished by the size and color of their granules.

Monocytes develop from blood-forming monoblasts in the bone marrow and are related to granulocytes. After circulating in the bloodstream for about a day, monocytes enter body tissues to become macrophages, which can destroy some germs by surrounding and digesting them. Macrophages also help lymphocytes recognize germs and make antibodies to fight them. Any of the blood-forming myeloid or lymphoid cells from bone marrow can turn into a leukemia cell. Once this change takes place, the leukemia cells no longer mature in a normal way. Leukemia cells often reproduce quickly, but in most cases the problem is that they don’t die when they should. They survive and build up in the bone marrow. Over time, these cells spill into the bloodstream and spread to other organs, where they can keep other cells in the body from doing their jobs. Types of leukemia Not all leukemias are the same. There are 4 main types of leukemia. Knowing the specific type helps doctors better predict each patient’s prognosis (outlook) and select the best treatment.

Acute leukemia versus chronic leukemia The first factor in classifying a patient’s leukemia is whether most of the abnormal cells look like normal white blood cells (mature) or look more like stem cells (immature). In acute leukemia, the leukemia cells are immature blood cells (called blasts). These leukemias are fast growing because normal blast cells divide quickly. But the leukemia cells don’t divide any more often than normal blast cells do. They just don’t stop dividing when normal blast cells would. Without treatment, most patients with acute leukemia would live only a few months. Some types of acute leukemia respond well to treatment, and many patients can be cured. Other types of acute leukemia have a less favorable outlook. In chronic leukemia, the leukemia cells are more mature cells, but they are not completely normal. They generally don’t fight infection as well as normal white blood cells. And they survive longer, build up, and crowd out normal cells. Chronic leukemias tend to progress over a longer period of time, and most patients can live with them for many years. But chronic leukemias are generally harder to cure than acute leukemias.

Myeloid leukemia versus lymphocytic leukemia The other main factor in classifying leukemia is the type of bone marrow cells that are affected. Myeloid leukemias start in immature forms of myeloid cells – white blood cells (other than lymphocytes), red blood cells, or platelet-making cells (megakaryocytes). They are also known as myelocytic, myelogenous, or non-lymphocytic leukemias. Lymphocytic leukemias start in immature forms of lymphocytes. They are also known as lymphoid or lymphoblastic leukemias. Lymphomas are also cancers that start in lymphocytes. But whereas lymphocytic leukemias develop from cells in the bone marrow, lymphomas develop from cells in lymph nodes or other organs. By considering whether leukemias are acute or chronic and whether they are myeloid or lymphocytic, they can be divided into 4 main types: Acute myeloid (or myelogenous) leukemia (AML) Lymphoid Tissue Lymphoid Tissues Bone Marrow The bone marrow gives rise to all of the cells engaged in the defense mechanisms of the body (with minor exceptions).

In babies it is found in all the bones, but moving through puberty it is replaced in the long bones by fat so that in adults it is found only in the central bones, such as the ischium. The key cells in bone marrow are the hematopoietic stem cells, which give rise to the lymphoid stem cells and the myeloid stem cells. Lymphoid stem cells give rise to the lymphocytes, which specifically identify foreign molecules and cells. The myeloid stem cells give rise to all of the other blood cells, including red blood cells. Cells Derived From Hematopoietic Stem Cells Let's make of list of the important cells to use for reference as we talk further about each of the types. (But we put off red blood cells until the spring.) Lymphocytes. Lymphocytes are the only cells capable of adaptively (specifically) making the molecules (antibodies and T cell receptors) that specifically recognize antigens, which are molecules foreign to the body. B-Lymphocytes. Cells that produce antibodies. Usually simply called "B cells". Helper T Lymphocytes. Cells with T cell receptors that activate macrophages and that help B cells develop their response.

T cells are usually simply called "T cells". Cytotoxic T Lymphocytes. Cells with T cell receptors that kill virally infected cells and certain cancer cells. Regulatory T Lymphocytes. Cells that suppress the functioning of other T cells. Natural Killer Cells. Cells that kill virally infected cells, but are part of the innate rather than adaptive (specific) immune response. Macrophages. Long-lived phagocytes that are important in initiating various aspects of inflammation and the immune response. They also predominate in chronic inflammation. In the blood they are called monocytes. Dendritic Cells. Collect antigen out in the tissues and carry it to ymph nodes in order to start an adaptive (specific) immune response. Neutrophils. Shorted-lived phagocytes that quickly enter the tissues at a site of an infection. Present in acute inflammation. Eosinophils. Specialized for attacking helminth worms. Platelets. Small "cells" important for blood clotting. Many bud off of one cell in the bone marrow and thus do not have a nucleus. Red Blood Cells. Lymph Now is a good time to outline the main fluid compartments in the body: Intracellular Fluid.

This is simply the fluid that is found inside cells. For a 70 kg (154 lb) person, this is about 28 liters. Extracellular Fluid. This, of course, is the fluid that is outside cells. In our 70 kg person, this is about 14 liters. It can be subdivided into two main compartments. (Ignoring certain relatively small volumes such as the cerebrospinal fluid and synovial fluid in joints.) Blood Plasma. This is the fluid portion of the blood. Red blood cells make up a little less than half of the blood, so that there is about 3 liters in our example. Interstitial Fluid. This is the extracellular fluid that is outside of blood vessels and surrounding the cells of the body. It is about 11 liters in volume. Intracellular fluid is very different in composition to the others and is very carefully regulated by the plasma membrane of each cell. The blood plasma and interstitial fluid are similar, but not identical. The wall of a capillary consists of only the endothelium, which consists of one layer of flat cells.

The endothelium in most capillaries (with some important exceptions) are quite permeable to molecules smaller than proteins. Thus, if you take blood and subtract the blood cells and blood proteins, you have the composition of most interstitial fluid. However, this breaks down in a region of inflammation, which entails a significant increase in the permeability of blood capillaries. Lymph is derived directly from the interstitial fluid and thus has exactly the same composition. Lymphatic capillaries are found in the tissues throughout the blood and accept interstitial fluid directly. They have flap-like openings in their walls, which allow even cells to enter. The lymphatic vessels drain away the small, net excess of interstitial fluid that forms as fluid leaves the circulatory capillaries. This is quite variable, but totals roughly 2 liters per day in a healthy person. By contrast, the heart pumps 2 liters of blood in about 20 seconds in a resting person. Observe in the above figure that microbes infecting the interstitial fluid slowly find their way into the lymph, which then slowly flows through ever largers lympatic vessels towards a big vein in the chest.

The lympathic vessels are very thin-walled, have occasional valves, and a small amount of smooth muscle. The slow, steady formation of lymph and simple, ordinary compressions of the tissues are usually enough to create the slow flow. Lymph Nodes But as the lymph flows from the lymphathic capillaries to the circulatory system, it inevitably must percolate through one or more lymph nodes. These are found especially in the neck, armpits, groin, and all along the back of the abdomen and thorax. We will study the structure of lymph nodes in lab. Here, note that lymph enters the node around its periphery in the subcapsular space and then percolates through the lymph node to its concave side, where it leaves in another lymphatic vessel. Note the microbe entering the lymph node. Recall, also, that dendritic cells travel from the tissues to the lymph nodes. As lymph moves through the lymph node, it encounters huge numbers of lymphocytes, and it is usually here that a specific immune response develops; this is where the various events take place that will soon be our main topic. The B cell response takes place in the lymphoid follicles, which are shown as circles in the figure.

On the other hand, T cells are found mainly in the paracortical area just beyond the follicles. While not shown in the figure, lymph nodes have circulatory capillaries just like other tissues. In the paracortical area, the small thin-walled vessels just after the capillaries are called high endothelial venules. Here is where lymphocytes in the blood bind cell adhesion molecules, cross the endothelium, and enter a lymph node. Lymphocytes need to move between the various lymph nodes of the body, so that immunity developed in one lymph node spreads to lymph nodes throughout the body. Also, a lymph node encountering an active infection will recruit additional lymphocytes by expressing more cell adhesion molecules that bind lymphocytes moving through the blood. Spleen The white pulp of the spleen has the same types of cells as a lymph node. But it is focused on microbes in the blood rather than microbes in the interstitial fluid. The red pulp destroys aged red blood cells. More later. MALT Epithelia lined by mucus are a logical place for pathogens to gain entry to the internal environment of the body.

Unlike the skin, with its dry, keratinized stratified squamous epithelia, epithelia in the digestive, respiratory and urinary systems are lined by living cells. Because these epithelia are such likely sites for colonization by pathogens, special aggregations of lymphoid tissue are closely associated with the epithelia. These aggregations are called mucosal associated lymphoid tissue (MALT). Microscopically, most of this are clusters of cells in the interstitial fluid directly below the epithelia. These cells are much like those in a lymph node, with a preponderance of lymphocytes. Some of these aggregations are quite large, such as the tonsils and the Peyer's patches in the distal part of the small intestine. The tonsils and Peyer's patches have follicles, just like the lymph nodes. In other places, the MALT consists of small, simple, scattered aggregations. Cells move between all types of MALT and lymph nodes, especially those in the abdomen. In this way, the immunological capabilites are spread throughout the MALT and even throughout the body. Mucosal surfaces have one challenge that is not present in other areas of the body.

For a moment, take the point of view of a pathogen. One option might be to cross the epithelium and enter the interstitial fluid. But here you immediately encounter phagocytes and other heavy hitters of the immune system. Why not simply bind to the apical surface of the epithelium and remain there, enjoying your metabolism and reproduction? Here you are somewhat separated by the immune system. Indeed, this is a logical move and many microbes do just that. Because of this, MALT has some additional special mechanisms to deal with pathogens in the lumen. Refer to the figure to the right. Their moist apical surfaces are covered by mucus, which provides a first line of defense. The first step for an effective pathogen is to bind somehow to the epithelial cells. In order for the immune system to respond to these microbes, their molecules need to be transported to the other cells of the MALT or a nearby lymph node. Notice the dendritic cell in the figure with one of its long, characteristic extentions capturing a microbe in the lumen. Also, the epithelium itself may have special M cells. These also engulf a microbe and transfer its molecules to the MALT.

While not shown in the figure, there are also some lymphocytes embedded in the epithelium lining the intestines. These are programmed to respond to some of the more commonly encountered microbes. The B lymphocytes in the MALT tend to make IgA. This is because a dimer of this antibody can bind to the basal surface of the epithelium, can be transfered to the apical surface and then can be released. In the lumen it binds to the surface of a microbe. This can prevent the microbe from binding to the epithelium and agglutinate it with other identical microbes into clumps. Cutaneous Lymphoid Tissue The epidermis of the skin contains a network of Langerhans cells, which are a type of dendritic cell. These phagocytes capture antigen, release from the epidermis and migrate to lymph nodes to start an adaptive (specific) immune response. Under the epidermis there are macrophages and T cells, much like elsewhere in the body. Thymus The thymus is a nondescript appearing organ that lies just above the heart. It is here that T cells develop their surface molecules and are selected. Again, more later.

What is chronic myeloid leukemia? What is chronic myeloid leukemia? Normal bone marrow and blood What is chronic myeloid leukemia? Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer? Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, is a type of cancer that starts in certain blood-forming cells of the bone marrow. In CML, a genetic change takes place in an early (immature) version of myeloid cells - the cells that make red blood cells, platelets, and most types of white blood cells (except lymphocytes). This change forms an abnormal gene called BCR-ABL, which turns the cell into a CML cell. The leukemia cells grow and divide, building up in the bone marrow and spilling over into the blood. In time, the cells can also settle in other parts of the body, including the spleen. CML is a fairly slow growing leukemia, but it can also change into a fast-growing acute leukemia that is hard to treat.

Most cases of CML occur in adults, but very rarely it occurs in children, too. In general, their treatment is the same as for adults. What is leukemia? Leukemia is a cancer that starts in the blood-forming cells of the bone marrow. When one of these cells changes and becomes a leukemia cell, it no longer matures normally. Often, it divides to make new cells faster than normal. Leukemia cells also don't die when they should. This allows them to build up in the bone marrow, crowding out normal cells. At some point, leukemia cells leave the bone marrow and spill into the bloodstream, often causing the number of white blood cells in the blood to increase. Once in the blood, leukemia cells can spread to other organs, where they can prevent other cells in the body from functioning normally. Leukemia is different from other types of cancer that start in organs such as the lungs, colon, or breast and then spread to the bone marrow. Cancers that start elsewhere and then spread to the bone marrow are not leukemia. Not all leukemias are the same. Knowing the specific type of leukemia helps doctors better predict each patient's prognosis (outlook) and select the best treatment. What is a chronic leukemia?

Whether leukemia is acute or chronic depends on whether most of the abnormal cells are immature (and are more like stem cells) or mature (and are more like normal white blood cells). In chronic leukemia, the cells can mature partly but not completely. These cells may look fairly normal, but they are not. They generally do not fight infection as well as normal white blood cells do. The leukemia cells survive longer than normal cells, and build up, crowding out normal cells in the bone marrow. Chronic leukemias can take a long time before they cause problems, and most people can live for many years. But chronic leukemias are generally harder to cure than acute leukemias. What is a myeloid leukemia? Whether leukemia is myeloid or lymphocytic depends on which bone marrow cells the cancer starts in. Myeloid leukemias (also known as myelocytic, myelogenous, or non-lymphocytic leukemias) start in early myeloid cells -- the cells that become white blood cells (other than lymphocytes), red blood cells, or platelet-making cells (megakaryocytes) . What are the other types of leukemia?

There are 4 main types of leukemia, based on whether they are acute or chronic, and myeloid or lymphocytic: Chronic lymphocytic leukemia (CLL) In acute leukemias, the bone marrow cells cannot mature the way they should. These immature cells continue to reproduce and build up. Without treatment, most people with acute leukemia would only live a few months. Some types of acute leukemia respond well to treatment, and many patients can be cured. Other types of acute leukemia have a less favorable outlook. Lymphocytic leukemias (also known as lymphoid or lymphoblastic leukemia) start in the cells that become lymphocytes. Lymphomas are also cancers that start in those cells. The main difference between lymphocytic leukemias and lymphomas is that in leukemia, the cancer cell is mainly in the bone marrow and blood, while in lymphoma it tends to be in lymph nodes and other tissues. Chronic myelomonocytic leukemia (CMML) is another chronic leukemia that starts in myeloid cells. For more information on this type of cancer, see Leukemia: Chronic Myelomonocytic . The rest of this information is only about chronic myeloid leukemia (CML).

<!-- SS_END_OPENREGIONMARKER(region1)--> <!-- SS_BEGIN_CLOSEREGIONMARKER(region1)--> Fatty tissue | definition of fatty tissue by Medical dictionary Fatty tissue | definition of fatty tissue by Medical dictionary Related to fatty tissue: lipoma tissue adipose tissue connective tissue made of fat cells in a meshwork of areolar tissue. areolar tissue connective tissue made up largely of interlacing fibers. bony tissue osseous tissue . brown adipose tissue (brown fat tissue) brown fat . bursa-equivalent tissue (bursal equivalent tissue) a hypothesized lymphoid tissue in nonavian vertebrates including human beings, equivalent to the bursa of Fabricius in birds: the site of B lymphocyte maturation. It now appears that B lymphocyte maturation occurs primarily in the bone marrow. cancellous tissue the spongy tissue of bone. cartilaginous tissue the substance of cartilage. chordal tissue the tissue of the notochord. chromaffin tissue a tissue composed largely of chromaffin cells, well supplied with nerves and vessels; it occurs in the adrenal medulla and also forms the paraganglia of the body.

cicatricial tissue the dense fibrous tissue forming a cicatrix , derived directly from granulation tissue ; called also scar tissue . connective tissue the tissue that binds together and is the support of the various structures of the body; see also connective tissue . elastic tissue connective tissue made up of yellow elastic fibers, frequently massed into sheets. endothelial tissue peculiar connective tissue lining serous and lymph spaces. epithelial tissue a general name for tissues not derived from the mesoderm. erectile tissue spongy tissue that expands and becomes hard when filled with blood. fatty tissue connective tissue made of fat cells in a meshwork of areolar tissue. fibrous tissue the common connective tissue of the body, composed of yellow or white parallel elastic and collagen fibers. gelatinous tissue mucous tissue . granulation tissue material formed in repair of wounds of soft tissue, consisting of connective tissue cells and ingrowing young vessels; it ultimately forms cicatrix. gut-associated lymphoid tissue (GALT) lymphoid tissue associated with the gut, including the tonsils, Peyer's patches, lamina propria of the gastrointestinal tract, and appendix. indifferent tissue undifferentiated embryonic tissue.

interstitial tissue connective tissue between the cellular elements of a structure. lymphadenoid tissue tissue resembling that of lymph nodes, spleen, bone marrow, tonsils, and lymph vessels. lymphoid tissue a latticework of reticular tissue whose interspaces contain lymphocytes . mesenchymal tissue embryonic connective tissue composed of stellate cells and a ground substance of coagulable fluid. mucous tissue a jellylike connective tissue, such as occurs in the umbilical cord. Called also gelatinous tissue . muscular tissue the substance of muscle. myeloid tissue red bone marrow . nerve tissue (nervous tissue) the specialized tissue forming the elements of the nervous system. osseous tissue the specialized tissue forming the bones. reticular tissue (reticulated tissue) connective tissue composed predominantly of reticulum cells and reticular fibers. sclerous t's the cartilaginous, fibrous, and osseous tissues. skeletal tissue the bony, ligamentous, fibrous, and cartilaginous tissue forming the skeleton and its attachments. splenic tissue red pulp . subcutaneous tissue the layer of loose connective tissue directly under the skin.

tissue typing identification of tissue types for purposes of predicting acceptance or rejection of grafts and transplants . The process and purposes of tissue typing are essentially the same as for blood typing. The major difference lies in the kinds of antigens being evaluated. The acceptance of allografts depends on the hla antigens (HLA); if the donor and recipient are not HLA identical, the allograft is rejected, sometimes within minutes. The HLA genes are located in the major histocompatibility complex , a region on the short arm of chromosome 6, and are involved in cell-cell interaction, immune response , organ transplantation, development of cancer, and susceptibility to disease. There are five genetic loci, designated HLA-A, HLA-B, HLA-C, HLA-D, and HLA-DR. At each locus, there can be any of several different alleles. Each person inherits one chromosome 6 from the mother and one from the father; that is, each parent transmits to the child one allele for each kind of antigen (A, B, C, D, and DR).

If the parents are different at both alleles of a locus, the statistical chance of one sibling being identical to another is one in four (25 per cent), the chance of being identical at one allele only (half-identical) is 50 per cent, and the chance of a total mismatch is 25 per cent. Techniques for Tissue Typing. Histocompatibility testing involves several basic methods of assay for HLA differences. The most widely used method uses the polymerase chain reaction to compare the DNA of the person, organ, or graft being tested with known pieces of the genes encoding MHC antigens. The variability of these regions of the genes determines the tissue type of the subject. Serologic methods are used to detect serologically defined antigens on the surfaces of cells. In general, HLA-A, -B, and -C determinants are primarily measured by serologic techniques. A second method, involving lymphocyte reactivity in a mixed lymphocyte culture, for determining HLA-D or lymphocyte-defined antigens, is now only rarely used. Essentially, the serologic method is performed by incubating target lymphocytes (isolated from fresh peripheral blood) with antisera that recognize all known HLA antigens.

The cells are spread in a tray with microscopic wells containing various kinds of antisera and are incubated for 30 minutes, followed by an additional 60-minute complement incubation. If the lymphocytes have on their surfaces antigens recognized by the antibodies in the antiserum, the lymphocytes are lysed. A dye is added to show changes in the permeability of the cell membrane and cellular death. The proportion of cells destroyed by lysis indicates the degree of histologic incompatibility. If, for example, the lymphocytes from a person being tested for HLA-A3 are destroyed in a well containing antisera for HLA-A3, the test is positive for this antigen group. white adipose tissue (yellow adipose tissue) the adipose tissue composing the bulk of the body fat. fat·ty tis·sue 2. in some animals, brown fat . fatty tissue Epithelium. erectile tissue Spongy tissue, the spaces of which fill with blood, causing it to harden and expand. It is found in the penis, clitoris, and nipples. fatty tissue Fat. fibrous tissue Connective tissue consisting principally of collagen fibers.

Also called white fibrous or dense connective tissue; may be regular (parallel fibers) or irregular. gelatiginous tissue Tissue from which gelatin may be obtained by treating it with hot water. glandular tissue A group of epithelial cells capable of producing secretions. granulation tissue The newly formed vascular and connective tissue produced in the early stages of wound healing. hard tissue In dentistry, the term used to denote any of the three calcified tissue components of the tooth: enamel, dentin, and cementum. homologous tissues Tissues that are identical in structure. indifferent tissue Tissue composed of undifferentiated cells as in embryonic tissue. interstitial tissue Connective tissue that forms a network with the cellular portions of an organ. lymphadenoid tissue Aggregates of lymphatic tissue found in the spleen and lymph nodes. lymphoid tissue Collections of lymphocytes in all stages of development found in the spleen, thymus, lymph nodes, lymph nodules of the digestive tract (tonsils, Peyer's patches), and the respiratory, urinary, and reproductive tracts. mesenchymal tissue Firm connective tissue such as bone and cartilage. skeletal tissue Bone.

soft tissue Any noncalcified tissue in the body. This term is especially used in relation to muscles, tendons, ligaments, skin, fat, and other connective tissues that are occasionally the source of pain when they are injured. Unlike bones or joints, which can be fractured or dislocated, soft tissues are bruised or inflamed by trauma. In surgery, soft tissues are dissected. By contrast, components of the (hard) bony skeleton are sawed, chiselled, or drilled. Soft tissues include all types of tissue except bone, i.e., all epithelial, muscle, and nerve tissue, as well as connective tissue excluding bone. splenic tissue The highly vascular splenic pulp. subcutaneous tissue pertaining to or characterized by fat. See also adipose . fatty acids organic compounds of carbon, hydrogen and oxygen that are esterified with glycerol to form fat. All fats are esters of fatty acids and glycerol, the fatty acids accounting for 90% of the molecule of most natural fats. A fatty acid consists of a long chain of carbon atoms with a carboxylic acid group at one end. Saturated fatty acids have no double bonds in the carbon chain.

The medium and long chain fatty acids are solid at room temperature and are the components of the common animal fats, such as butter and lard. Unsaturated fatty acids contain one or more double bonds. The unsaturated fatty acids are liquid at room temperature and are found in oils such as olive oil and linseed oil. Polyunsaturated fatty acids have two or more double bonds. Volatile fatty acids (VFAs) including acetic, butyric and propionic acids are produced in large quantities in the rumen by the fermentative digestion of cellulose. Much of the energy consumption of ruminants comes from these VFAs in the situation in which other animals use glucose. See also 3-omega fatty acid (below). fatty acid nutritional deficiency a secondary deficiency occurs in pigs on high-calcium diets. This may have a connection with parakeratosis of pigs caused by zinc deficiency and calcium excess in the diet. Requirements for dietary fat in dogs and cats are usually expressed as the essential linoleic acid and arachidonic acid . fatty acid synthase in bacteria, a multiprotein complex; in mammals, a single multifunctional protein important in the synthesis of palmitate as a major source of fatty acids.

fatty acyl CoA generic term for long hydrocarbon chains, generally between C12 and C20, linked via thioester to coenzyme A. fatty acyl CoA:cholesterol acyltransferase enzyme (ACAT) catalyzing the transfer of fatty acyl group to cholesterol, irreversible physiologically. Its action regulates the number of LDL receptors by converting excess cholesterol (which inhibits LDL receptors) to cholesterol esters. branched chain fatty acids fatty acids usually containing a methyl branch; lowers the melting point compared with the equivalent straight chain fatty acid. fatty casts deposit of fat globules in a tissue. essential fatty acids (EFA) essential fatty acids. fatty liver accumulation of fat in a liver beyond the level which is normally encountered may be a result of a normal physiological response to increased peripheral lipolysis, obesity or the action of hepatotoxins. fatty liver disease see fat cow syndrome. fatty liver syndrome 1. a disease of laying birds housed in battery cages. The cause is unknown. Affected birds are significantly heavier, there is a fall in egg production and they die acutely of liver rupture. The liver is greasy, mushy in consistency and yellow in color.

2. a severe fatty accumulation in the liver and hypertriglyceridemia that may develop in obese cats that are anorexic. There is jaundice, weight loss, neurological signs and a high mortality. Called also idiopathic feline hepatic lipidosis. omega-3 (n-3) fatty acids include α-linolenic acid, eicosapentanoic acid, docosahexanoic acid. High concentrations found in cold water marine (fish) oils. omega-6 (n-6) fatty acids found in terrestrial plants, including safflower oil, corn oil and evening primrose oil, which is a rich source of linoleic and arachidonic acids. fatty tissue connective tissue made of fat cells in a meshwork of areolar tissue. Basophil - MedFriendly.com Basophil A basophil is a type of white blood cell present in the blood. White blood cells help protect the body against diseases and fight infections. Basophils help protect the body against disease and infections by eating some types of bacteria, foreign substances, and other cells. WHAT ARE SOME OTHER CHARACTERISTICS OF BASOPHILS?

Basophils will look black and blue or dark purple when stained by a basic dye, such as Wright stain. Dyes are colored stains that are used in laboratories, often to tell cells apart from one another. The nuclei of basophils come in various forms. The word "nuclei" means more than one nucleus. A nucleus is the center of a cell. A basophil under the microscope. Thus, the centers of basophils appear in various forms. A unique characteristic of basophils, compared to other white blood cells, is that they usually do not increase in numbers in response to sudden infections or diseases. However, sometimes basophils will increase in response to sudden infections or diseases. Another characteristic of basophiles is that their cytoplasm (a gel-like substance that fills up a cell) is mostly made of many large, rough-looking, grain-like particles. These grain-like particles can be seen under the microscope, but may sometimes cover the nucleus. The grain-like particles may decrease in numbers in response to allergic reactions and may increase in response to some types of inflammation.

"Where Medical Information is Easy to Understand"™ The grain-like particles of basophils contain the following substances: histamine, leukotrienes, and heparin. Histamine is a substance found in all cells that is released during allergic and inflammatory reactions. Leukotrienes are substances in the body that produce allergic and inflammatory reactions, similar to histamine. Heparin is a naturally occurring substance in the body that prevents clotting (blood fluid coming together as a solid). WHAT DOES A BASOPHIL LOOK LIKE? A basophil is pictured above to the top right. WHAT PERCENT OF WHITE BLOOD CELLS ARE BASOPHILS? Approximately 0.4% to 1% of white blood cells are basophils. This is the normal range of basophils on bloodwork tests. Basophils are the least common type of white blood cell. WHAT CAN CAUSE THE LEVEL OF BASOPHILS TO BE TOO HIGH? The level of basophils can be too high in response to an infection from a virus. Removal of the spleen can also cause basophils to be too high.

The spleen is an organ that helps fight infection and removes and destroys worn-out red blood cells. Increased estrogen can cause basophils to be too high as well. Estrogen is a type of hormone that promotes the growth of some physical female sexual characteristics. Hormones are types of chemicals in the body that affect other cells. Basophils can be high when inflammation in the body is healing. Basophils can also be high in diseases that cause an increase in myeloid tissue. Myeloid tissue is a type of bone marrow (a tissue found inside bones) that has many fibers . One such condition in which there is an increase in myeloid tissue is polycythemia vera. Polycythemia vera is a condition of unknown cause in which there is a long-term increase in red blood cells and other types of cells. Another such condition is myelofibrosis, in which the normal bone marrow is replaced by fibrous tissue (the connective tissue of the body). Chronic myelocytic leukemia (cancer of blood-forming tissues) can also cause a rise in basophils.

Cancer is a group of diseases in which symptoms are due to an abnormal and excessive growth of cells in one of the body organs or tissues. Basophils can also be increased due to some conditions that cause inflammation. Examples are asthma (difficulty breathing due to narrowing of the airway passage), chronic dermatitis (a long-term inflammation of the skin), and chronic inflammation of the sinuses. Sinuses are openings in the bone that often contain fluid. Another inflammatory condition that can cause an increase in basophils is Crohn's disease. Crohn's disease is a condition that causes inflammation of the intestine . The intestine is a tube shaped structure that is part of the digestive tract. It stretches from an opening in the stomach to the anus (rear end) and occupies most of the lower parts of the belly. Hypothyroidism can cause basophils to be too high. Hypothyroidism is a condition in which the thyroid gland is underactive. The thyroid gland is a butterfly-shaped organ located in front of the neck that produces a natural chemical known as hormones that affect virtually every cell in the body and many functions such as disease fighting, heart rate, energy level, and skin condition.

Hemolytic anemia can cause an increase in basophils. Hemolytic anemia is a disorder that causes the red blood cells to be destroyed to early. Red blood cells help carry oxygen in the blood. Another cause of increased basophils is Hodgkins lymphoma, which is a painless (yet very serious), worsening condition in which lymphoid tissue is enlarged. Lymphoid tissue is a type of tissue that contains lympocytes. Lympocytes are types of white blood cells that help the body fight against disease. WHAT CAN CAUSE THE LEVEL OF BASOPHILS TO BE TOO LOW? Basophils can be too low in people who have severe allergies. It can also be low in pregnant women and people under stress. Hyperthyroidism can also cause basophils to be too low. Hyperthyroidism is a condition in which the thyroid gland is overactive. See the previous section for a description of the thyroid gland. Basophils can be low in people who are taking corticosteroids. Corticosteroids are a group of drugs that act similarly to a natural chemical in the body known as corticosteroid hormone.

Corticosteroid hormones control the body's use of nutrients and the amount of water and salts in the urine. WHAT ARE OTHER MEANINGS OF THE TERM, BASOPHIL? Basophil is also used to describe any type of cell with grain-like particles in the cytoplasm (the gooey substance inside of cells) that stain in a specific way when exposed to basic dyes. Dyes are colored stains that are used in laboratories, often to tell cells apart from one another. Basophil is also used as an adjective to describe parts of tissues that stain well when exposed to dyes. This meaning of basophil is also known as basophilic. WHAT ELSE ARE BASOPHILS CALLED? Basophils are also known as a basophiles, basophilic leukocytes, basocytes, basophilocytes, and mast leukocytes. WHAT IS THE ORIGIN OF THE TERM "BASOPHIL"?

Basophil comes from the Greek word "basis" meaning "foundation," and the Greek word "philein" meaning "to love." Put the two words together and you have "to love foundation." AP Ch 7 Flashcards The types of tissue that make up bone are: Definition Osseous, adipose, nervous, blood, bone marrow, and fibrous connective tissue Term Where does spongy bone occur? Definition Ends of bone, in the middle of thin bones, in the middle of the shaft Term What is the function of the epiphysis? Definition Enlarged to strengthen joint and provide added surface area for attachments of tendons and ligaments. Term The layer of hyaline cartilage where one bone meets another, allows for smooth movement: Definition Articular cartilage Term In children, the hyaline cartilage that separates the marrow of the epiphysis and diaphysis; zone where bones grow in length: Definition Also called "ectopic ossification"; may occur in lungs, brain, eyes, muscles, tendons, or arteries Term What happens during Appositional growth? Definition 1. Osteoblasts on deep side of periosteum deposit osteoid tissue 2.

Become trapped as tissue calcifies 3. Lay down matrix in layers parallel to surface 4. Forms circumferential lamellae over surface 5. Osteoclasts of endosteum enlarge marrow cavity Term Canaliculi: definition, function, type of cell junction? Definition Small channels or canals between lacunae that allow osteocytes to exchange wastes and bring metabolites in; osteocytes send out cytoplasmic processes into the canaliculi and contact neighboring cells through gap junctions. Term Which cells have a ruffled border and secrete hydrochloric acid? Definition

Question: 'Myeloid Tissue' is another name for what?
Answer: BONE MARROW